MIAMI (AP) _ Investigators at the most difficult crash scene they can recall probed inch-by-inch in inky water and Everglades muck and found the submerged engines of ValuJet Flight 592.

But exactly how to remove the wreckage and 109 bodies from the alligator- and snake-infested swamp remained as uncertain as the cause of smoke that filled the cockpit and cabin before Saturday's crash.

The search was to resume today with Navy salvage specialists.

``Given the environment out in the swamp there, with the mud and the water particularly, the combination, it is very, very tough to figure out how we're going to get the aircraft out,'' Robert Francis, National Transportation Safety Board vice chairman, said Sunday night.

Among ideas being considered were draining a portion of the swamp or extending a dike to the site. But officials from the Army Corps of Engineers, the Navy, state and local agencies and the NTSB remained ``nowhere near a consensus,'' Francis said.

Some body parts were found Sunday, police sources said on condition of anonymity, but federal officials said they were not aware of any such discoveries.

The grim task proceeded in an eerie, surreal atmosphere as the vast Everglades seemed to have swallowed the plane. Even at the spot where the aircraft pierced the water, divers literally groped for clues.

``They're down to less than an inch as far as underwater visibility. A lot of it is being done by feel,'' said NTSB investigator Greg Feith.

The New York Times quoted a detective as saying searchers prodding with poles located what may be a segment of the plane's fuselage, measuring some 20-30 feet wide and 60-70 feet long. Officials would not confirm the report.

NTSB officials said a fragment 8 feet long was the largest they had seen. Both engines were found in about 2 feet of water, the NTSB said.

The water ranged from 6 inches to 5 feet deep. Beneath that was muck that some locals say can be 30 to 40 feet deep.

Navy divers, specialists in underwater salvage recovery, were bringing sonar equipment with which officials hope they will locate the plane's flight data recorders.

Senior NTSB investigators with hundreds of crash investigations behind them called the site, far from roads and accessible only by airboats, ``the most difficult scene that they have ever encountered,'' Francis said.

Divers had to be concerned with getting snagged in wreckage, and alligators and deadly water moccasins are common in the swamp.

Mosquitoes and heat in the mid-80s also plagued recovery workers, prompting Howard and Gloria Sexton to launch a small relief effort. The couple drove from their home in Boca Raton with a van load of donated insect repellent, bottled water and candy bars for the workers.

``I grew up in a town where everybody took care of everybody else,'' Howard Sexton explained.

The swamp yielded pieces of clothing Sunday, in addition to a family photo album and a floating airplane seat that were found Saturday.

Clearer pictures of the passengers also emerged Sunday: a Baptist church organist and his wife on a dream vacation, a young man preparing for missionary work in his native Venezuela, a mother and her daughter who had become ``real friends'' in recent years.

Also among the victims were San Diego Chargers running back Rodney Culver and his wife, Karen, of Woodstock, Ga.

Flight 592 took off Saturday afternoon en route to Atlanta but the crew soon reported smoke in the cockpit and cabin and asked to turn back. The plane crashed about 15 miles northwest of Miami International Airport.

The source of the cockpit smoke was unknown.

Possible causes include an electrical short circuit, an overheated tire on the nose wheel that retracts under the cockpit, or engine problems because air bled from the engines is used to pressurize the cabin, said aviation consultant David Stempler. He emphasized he was not speculating about causes in the ValuJet case.

The Atlanta-based discount airline has had at least three accidents since it began operations in 1993. The most serious was a runway fire last year that destroyed a plane and burned a flight attendant.

Federal Aviation Administration records showed the crashed jet had returned to airports seven times over the past two years because of various maintenance problems, from an oil leak to loss of cabin pressure.

However, the plane had a thorough annual inspection in October and a routine inspection four days before the crash. But the FAA began a special investigation of the airline in February. FAA inspectors will ride in ValuJet cockpits over the next 30 days as part of stepped-up checks in the wake of the crash.

``If ValuJet had any reason to believe one of our airliners was unsafe, we would voluntarily ground it,'' said airline president Lewis Jordan.

Transportation Secretary Federico Pena and FAA Chairman David Hinson visited the crash site Sunday. At a news conference, Pena expressed confidence the airline was safe.

Family members of victims met with Pena later in the day, and he said he would try to meet their request to go out to the crash site.

Victims' loved ones struggled for words to convey their loss.

``There's no evidence of the plane. It's gone,'' said a stunned Bret Rugg, 41, of Richmond, Ind., whose wife, Terri, was on the plane. He had taken his two sons, ages 5 and 11, to meet their mother on her return from a cruise she made as a travel agency owner.

``I don't know what I'm going to do,'' he said.